/*      $OpenBSD: raw_ip.c,v 1.168 2026/07/16 12:21:40 bluhm Exp $      */
/*      $NetBSD: raw_ip.c,v 1.25 1996/02/18 18:58:33 christos Exp $     */

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)COPYRIGHT   1.1 (NRL) 17 January 1995
 *
 * NRL grants permission for redistribution and use in source and binary
 * forms, with or without modification, of the software and documentation
 * created at NRL provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgements:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 *      This product includes software developed at the Information
 *      Technology Division, US Naval Research Laboratory.
 * 4. Neither the name of the NRL nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as representing
 * official policies, either expressed or implied, of the US Naval
 * Research Laboratory (NRL).
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>

#include <net/if.h>
#include <net/if_var.h>

#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_mroute.h>
#include <netinet/ip_var.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_icmp.h>

#include <net/pfvar.h>

#include "pf.h"

struct inpcbtable rawcbtable;

/*
 * Nominal space allocated to a raw ip socket.
 */
#define RIPSNDQ         8192
#define RIPRCVQ         8192

/*
 * Raw interface to IP protocol.
 */

const struct pr_usrreqs rip_usrreqs = {
        .pru_attach     = rip_attach,
        .pru_detach     = rip_detach,
        .pru_bind       = rip_bind,
        .pru_connect    = rip_connect,
        .pru_disconnect = rip_disconnect,
        .pru_shutdown   = rip_shutdown,
        .pru_send       = rip_send,
        .pru_control    = in_control,
        .pru_sockaddr   = in_sockaddr,
        .pru_peeraddr   = in_peeraddr,
};

void    rip_sbappend(struct inpcb *, struct mbuf *, struct ip *,
            struct sockaddr_in *);

/*
 * Initialize raw connection block q.
 */
void
rip_init(void)
{
        in_pcbinit(&rawcbtable, 1);
}

int
rip_input(struct mbuf **mp, int *offp, int proto, int af, struct netstack *ns)
{
        struct mbuf *m = *mp;
        struct ip *ip = mtod(m, struct ip *);
        struct inpcb_iterator iter = { .inp_table = NULL };
        struct inpcb *inp, *last;
        struct in_addr *key;
        struct sockaddr_in ripsrc;

        KASSERT(af == AF_INET);

        memset(&ripsrc, 0, sizeof(ripsrc));
        ripsrc.sin_family = AF_INET;
        ripsrc.sin_len = sizeof(ripsrc);
        ripsrc.sin_addr = ip->ip_src;

        key = &ip->ip_dst;
#if NPF > 0
        if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
                struct pf_divert *divert;

                divert = pf_find_divert(m);
                KASSERT(divert != NULL);
                switch (divert->type) {
                case PF_DIVERT_TO:
                        key = &divert->addr.v4;
                        break;
                case PF_DIVERT_REPLY:
                        break;
                default:
                        panic("%s: unknown divert type %d, mbuf %p, divert %p",
                            __func__, divert->type, m, divert);
                }
        }
#endif
        mtx_enter(&rawcbtable.inpt_mtx);
        last = inp = NULL;
        while ((inp = in_pcb_iterator(&rawcbtable, inp, &iter)) != NULL) {
                KASSERT(!ISSET(inp->inp_flags, INP_IPV6));

                /*
                 * Packet must not be inserted after disconnected wakeup
                 * call.  To avoid race, check again when holding receive
                 * buffer mutex.
                 */
                if (ISSET(READ_ONCE(inp->inp_socket->so_rcv.sb_state),
                    SS_CANTRCVMORE))
                        continue;
                if (rtable_l2(inp->inp_rtableid) !=
                    rtable_l2(m->m_pkthdr.ph_rtableid))
                        continue;

                if (inp->inp_ip.ip_p && inp->inp_ip.ip_p != ip->ip_p)
                        continue;
                if (inp->inp_laddr.s_addr &&
                    inp->inp_laddr.s_addr != key->s_addr)
                        continue;
                if (inp->inp_faddr.s_addr &&
                    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
                        continue;

                if (last != NULL) {
                        struct mbuf *n;

                        mtx_leave(&rawcbtable.inpt_mtx);

                        n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
                        if (n != NULL)
                                rip_sbappend(last, n, ip, &ripsrc);
                        in_pcbunref(last);

                        mtx_enter(&rawcbtable.inpt_mtx);
                }
                last = in_pcbref(inp);
        }
        mtx_leave(&rawcbtable.inpt_mtx);

        if (last == NULL) {
                struct counters_ref ref;
                uint64_t *counters;

                if (ip->ip_p == IPPROTO_ICMP) {
                        m_freem(m);
                } else {
                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL,
                            0, 0);
                }
                counters = counters_enter(&ref, ipcounters);
                counters[ips_noproto]++;
                counters[ips_delivered]--;
                counters_leave(&ref, ipcounters);

                return IPPROTO_DONE;
        }

        rip_sbappend(last, m, ip, &ripsrc);
        in_pcbunref(last);

        return IPPROTO_DONE;
}

void
rip_sbappend(struct inpcb *inp, struct mbuf *m, struct ip *ip,
    struct sockaddr_in *ripsrc)
{
        struct socket *so = inp->inp_socket;
        struct mbuf *opts = NULL;
        int ret = 0;

        if (inp->inp_flags & INP_CONTROLOPTS || so->so_options & SO_TIMESTAMP)
                ip_savecontrol(inp, &opts, ip, m);

        mtx_enter(&so->so_rcv.sb_mtx);
        if (!ISSET(inp->inp_socket->so_rcv.sb_state, SS_CANTRCVMORE))
                ret = sbappendaddr(&so->so_rcv, sintosa(ripsrc), m, opts);
        mtx_leave(&so->so_rcv.sb_mtx);

        if (ret == 0) {
                m_freem(m);
                m_freem(opts);
                ipstat_inc(ips_noproto);
        } else
                sorwakeup(so);
}

/*
 * Generate IP header and pass packet to ip_output.
 * Tack on options user may have setup with control call.
 */
int
rip_output(struct mbuf *m, struct socket *so, struct sockaddr *dstaddr,
    struct mbuf *control)
{
        struct sockaddr_in *dst = satosin(dstaddr);
        struct ip *ip;
        struct inpcb *inp;
        int flags, error;

        inp = sotoinpcb(so);
        flags = IP_ALLOWBROADCAST;

        /*
         * If the user handed us a complete IP packet, use it.
         * Otherwise, allocate an mbuf for a header and fill it in.
         */
        if ((inp->inp_flags & INP_HDRINCL) == 0) {
                if ((m->m_pkthdr.len + sizeof(struct ip)) > IP_MAXPACKET) {
                        m_freem(m);
                        return (EMSGSIZE);
                }
                M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
                if (!m)
                        return (ENOBUFS);
                ip = mtod(m, struct ip *);
                ip->ip_tos = inp->inp_ip.ip_tos;
                ip->ip_off = htons(0);
                ip->ip_p = inp->inp_ip.ip_p;
                ip->ip_len = htons(m->m_pkthdr.len);
                ip->ip_src.s_addr = INADDR_ANY;
                ip->ip_dst = dst->sin_addr;
                ip->ip_ttl = inp->inp_ip.ip_ttl ? inp->inp_ip.ip_ttl : MAXTTL;
        } else {
                if (m->m_pkthdr.len > IP_MAXPACKET) {
                        m_freem(m);
                        return (EMSGSIZE);
                }

                m = rip_chkhdr(m, inp->inp_options);
                if (m == NULL)
                        return (EINVAL);

                ip = mtod(m, struct ip *);
                if (ip->ip_id == 0)
                        ip->ip_id = htons(ip_randomid());
                dst->sin_addr = ip->ip_dst;

                /* XXX prevent ip_output from overwriting header fields */
                flags |= IP_RAWOUTPUT;
                ipstat_inc(ips_rawout);
        }

        if (ip->ip_src.s_addr == INADDR_ANY) {
                error = in_pcbselsrc(&ip->ip_src, dst, inp);
                if (error != 0)
                        return (error);
        }

#ifdef INET6
        /*
         * A thought:  Even though raw IP shouldn't be able to set IPv6
         *             multicast options, if it does, the last parameter to
         *             ip_output should be guarded against v6/v4 problems.
         */
#endif
        /* force routing table */
        m->m_pkthdr.ph_rtableid = inp->inp_rtableid;

#if NPF > 0
        if (inp->inp_socket->so_state & SS_ISCONNECTED &&
            ip->ip_p != IPPROTO_ICMP)
                pf_mbuf_link_inpcb(m, inp);
#endif

        error = ip_output(m, inp->inp_options, &inp->inp_route, flags,
            inp->inp_moptions, &inp->inp_seclevel, 0);
        return (error);
}

struct mbuf *
rip_chkhdr(struct mbuf *m, struct mbuf *options)
{
        struct ip *ip;
        int hlen, opt, optlen, cnt;
        u_char *cp;

        if (m->m_pkthdr.len < sizeof(struct ip)) {
                m_freem(m);
                return NULL;
        }

        m = m_pullup(m, sizeof (struct ip));
        if (m == NULL)
                return NULL;

        ip = mtod(m, struct ip *);
        hlen = ip->ip_hl << 2;

        /* Don't allow packet length sizes that will crash. */
        if (hlen < sizeof (struct ip) ||
            ntohs(ip->ip_len) < hlen ||
            ntohs(ip->ip_len) != m->m_pkthdr.len) {
                m_freem(m);
                return NULL;
        }
        m = m_pullup(m, hlen);
        if (m == NULL)
                return NULL;

        ip = mtod(m, struct ip *);

        if (ip->ip_v != IPVERSION) {
                m_freem(m);
                return NULL;
        }

        /*
         * Don't allow both user specified and setsockopt options.
         * If options are present verify them.
         */
        if (hlen != sizeof(struct ip)) {
                if (options) {
                        m_freem(m);
                        return NULL;
                } else {
                        cp = (u_char *)(ip + 1);
                        cnt = hlen - sizeof(struct ip);
                        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                                opt = cp[IPOPT_OPTVAL];
                                if (opt == IPOPT_EOL)
                                        break;
                                if (opt == IPOPT_NOP)
                                        optlen = 1;
                                else {
                                        if (cnt < IPOPT_OLEN + sizeof(*cp)) {
                                                m_freem(m);
                                                return NULL;
                                        }
                                        optlen = cp[IPOPT_OLEN];
                                        if (optlen < IPOPT_OLEN + sizeof(*cp) ||
                                            optlen > cnt) {
                                                m_freem(m);
                                                return NULL;
                                        }
                                }
                        }
                }
        }

        return m;
}

/*
 * Raw IP socket option processing.
 */
int
rip_ctloutput(int op, struct socket *so, int level, int optname,
    struct mbuf *m)
{
        struct inpcb *inp = sotoinpcb(so);
        int error;

        if (level != IPPROTO_IP)
                return (EINVAL);

        switch (optname) {

        case IP_HDRINCL:
                error = 0;
                if (op == PRCO_SETOPT) {
                        if (m == NULL || m->m_len < sizeof (int))
                                error = EINVAL;
                        else if (*mtod(m, int *))
                                inp->inp_flags |= INP_HDRINCL;
                        else
                                inp->inp_flags &= ~INP_HDRINCL;
                } else {
                        m->m_len = sizeof(int);
                        *mtod(m, int *) = inp->inp_flags & INP_HDRINCL;
                }
                return (error);

        case MRT_INIT:
        case MRT_DONE:
        case MRT_ADD_VIF:
        case MRT_DEL_VIF:
        case MRT_ADD_MFC:
        case MRT_DEL_MFC:
        case MRT_VERSION:
        case MRT_ASSERT:
        case MRT_API_SUPPORT:
        case MRT_API_CONFIG:
#ifdef MROUTING
                switch (op) {
                case PRCO_SETOPT:
                        error = ip_mrouter_set(so, optname, m);
                        break;
                case PRCO_GETOPT:
                        error = ip_mrouter_get(so, optname, m);
                        break;
                default:
                        error = EINVAL;
                        break;
                }
                return (error);
#else
                return (EOPNOTSUPP);
#endif
        }
        return (ip_ctloutput(op, so, level, optname, m));
}

u_long  rip_sendspace = RIPSNDQ;
u_long  rip_recvspace = RIPRCVQ;

int
rip_attach(struct socket *so, int proto, int wait)
{
        struct inpcb *inp;
        int error;

        if (so->so_pcb)
                panic("rip_attach");
        if ((so->so_state & SS_PRIV) == 0)
                return EACCES;
        if (proto < 0 || proto >= IPPROTO_MAX)
                return EPROTONOSUPPORT;

        if ((error = soreserve(so, rip_sendspace, rip_recvspace)))
                return error;
        if ((error = in_pcballoc(so, &rawcbtable, wait)))
                return error;
        inp = sotoinpcb(so);
        inp->inp_ip.ip_p = proto;
        return 0;
}

int
rip_detach(struct socket *so)
{
        struct inpcb *inp = sotoinpcb(so);

        soassertlocked(so);

        if (inp == NULL)
                return (EINVAL);

#ifdef MROUTING
        ip_mrouter_done(so);
#endif
        in_pcbdetach(inp);

        return (0);
}

int
rip_bind(struct socket *so, struct mbuf *nam, struct proc *p)
{
        struct inpcb *inp = sotoinpcb(so);
        struct sockaddr_in *addr;
        int error;

        soassertlocked(so);

        if ((error = in_nam2sin(nam, &addr)))
                return (error);

        if (!((so->so_options & SO_BINDANY) ||
            addr->sin_addr.s_addr == INADDR_ANY ||
            addr->sin_addr.s_addr == INADDR_BROADCAST ||
            in_broadcast(addr->sin_addr, inp->inp_rtableid) ||
            ifa_ifwithaddr(sintosa(addr), inp->inp_rtableid)))
                return (EADDRNOTAVAIL);

        mtx_enter(&rawcbtable.inpt_mtx);
        inp->inp_laddr = addr->sin_addr;
        mtx_leave(&rawcbtable.inpt_mtx);

        return (0);
}

int
rip_connect(struct socket *so, struct mbuf *nam)
{
        struct inpcb *inp = sotoinpcb(so);
        struct sockaddr_in *addr;
        int error;

        soassertlocked(so);

        if ((error = in_nam2sin(nam, &addr)))
                return (error);

        mtx_enter(&rawcbtable.inpt_mtx);
        inp->inp_faddr = addr->sin_addr;
        mtx_leave(&rawcbtable.inpt_mtx);
        soisconnected(so);

        return (0);
}

int
rip_disconnect(struct socket *so)
{
        struct inpcb *inp = sotoinpcb(so);

        soassertlocked(so);

        if ((so->so_state & SS_ISCONNECTED) == 0)
                return (ENOTCONN);

        soisdisconnected(so);
        mtx_enter(&rawcbtable.inpt_mtx);
        inp->inp_faddr.s_addr = INADDR_ANY;
        mtx_leave(&rawcbtable.inpt_mtx);

        return (0);
}

int
rip_shutdown(struct socket *so)
{
        /*
         * Mark the connection as being incapable of further input.
         */

        soassertlocked(so);
        socantsendmore(so);

        return (0);
}

int
rip_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
    struct mbuf *control)
{
        struct inpcb *inp = sotoinpcb(so);
        struct sockaddr_in dst;
        int error;

        soassertlocked(so);

        /*
         * Ship a packet out.  The appropriate raw output
         * routine handles any massaging necessary.
         */
        memset(&dst, 0, sizeof(dst));
        dst.sin_family = AF_INET;
        dst.sin_len = sizeof(dst);
        if (so->so_state & SS_ISCONNECTED) {
                if (nam) {
                        error = EISCONN;
                        goto out;
                }
                dst.sin_addr = inp->inp_faddr;
        } else {
                struct sockaddr_in *addr;

                if (nam == NULL) {
                        error = ENOTCONN;
                        goto out;
                }
                if ((error = in_nam2sin(nam, &addr)))
                        goto out;
                dst.sin_addr = addr->sin_addr;
        }
#ifdef IPSEC
        /* XXX Find an IPsec TDB */
#endif
        error = rip_output(m, so, sintosa(&dst), NULL);
        m = NULL;

out:
        m_freem(control);
        m_freem(m);

        return (error);
}